Piano



(No Model.) 2 Sheets-Sheet 1. E. N. CUMMINGS.

PIANO.

No. 454,901. Patented June 30,1891.

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(No Model.) T 2 Sheets-Sheet 2. E. N. OUMMlNGS. PIANO.

No. 454,901. Patented June 30,1891.

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Wz'inesses Mic 8M UNITED STATES PATENT OFFICE.

EDlVARD N. CUMMINGS, OF LYNN, MASSACHUSETTS.

SPECIFICATION forming part of Letters Patent No. 454,901, dated June 30,1891. Application fi e February '7, 1890. Serial No. 339,548. (NoDlOdBl- To all whom, it may concern.-

Be it known that I, EDWARD N. CUMMINGS, a citizen of the United States,residing at Lynn, in the county of Essex and Commonwealth ofMassachusetts, have invented certain new and useful Improvements inPianos, of which the following is a full specification.

The object of my invention is to so construct the piano-plate andadjacent parts as to secure the greatest possible freedom from liabilityto get out of tune when once properly adjusted in this regard.

In pianos as commonly constructed the strings are held at one end to themetal plate and at the other to tuning-pins driven into a woodenpin-block separate from the plate, the pin-block being secured to theframe or skeleton independently of the plate. There are various ways ofdoing this; but ordinarily when a full plate is used the plate coversthe pin-block, holes being drilled through the plate considerably largerthan the pins to allow the same to enter the block underneath withoutbearing against the plate. On this account the distance from the pointof attachment of the string to the pin to the point where the pin entersthe pin-block is necessarily considerable, being rather more than thethickness of the plate. There is thus a great amount of leverage for thepin to spring and pry on the pin-block. The tension of the stringsbetween one end of the plate and the separate pin-block at the other endamounts to about fifteen tons, and it is obvious that the slightestinovement'of the parts, whether by the springing of the plate itself orof the pin-block, or by the turning of one of the pins therein, wouldseriously aifect the tune of the piano. The wooden pin-block, moreover,is constantly liable to shrinkage or warping or swelling, due to changesof weather or climate.

In my improved piano I decrease to a minimum the tendency of theinstrument to get out of tune in two ways, first, by the construction ofthe plate and pin-block in one piece and the peculiar arrangement andconstruction of plate-supporting frame and stays,

. whereby all springing of the plate itself or of the plate withreference to the pin-block is entirely prevented, and, second, by thearrangement of the tuning-pins, whereby they are so firmly held thatthey cannot be accidentally turned.

Of the accompanying drawings, which represent my improvement as appliedto an upright piano, Figure 1 shows in front elevation a diagram of theplate, showing the arrangement of strings, stay-bolts, the. Fig. 2 is arear perspective view of the skeleton or frame supporting the plate.Fig. 3 is a sectional elevation on a larger scale throughthe platesounding-board. and frame from top to bottom, and Fig. lis an enlargedplan view showing the arrangement of the tuning-pins in the pin-block.

In inyimproved instrument I do away with a separate pin-block and employa full metal plate A, having the bridge a and the pinblock A integraltherewith. The pin-block A is provided with holes at the proper placesto receive bushings T, of wood or any other suitable material, withinwhich bushings the tuning-pins P are tightly held. The bushings aremade, preferably, by first plugging the holes through the pin-block withthe wood or other material and then boring out the plug itself for thereception of the pin. By this construction the plug forming the bushing,being larger than the hole, is condensed in being driven into thepin-block, especially if wood is used for the bushing and the hole boredthrough the bushing is preferably smaller than the pin, so that when thepin, which is preferably provided with a fine screw-thread, is driveninto the bushing it is very firmly held therein. The pin-block A isrearwardly beveled on its upper side from the bridge down, as shown inFig. 3, and each string G being held at one end to the plate in anysuitable manner, as by the pin f, is car ried therefrom, first over abridge (I on the sounding-board, as hereinafter described, and then overthe bridge a directly to the tuning-pin P. By this construction thepressure-bar with its bolts, which is ordinarily used between the bridgea and the tuning-pin, is entirely done away with. In this way Ivery muchreduce the liability of the string to break, since when a pressure-baris used the strain on the string when tuning is not equally distributedthroi'igh the string,but is greatest between the bridge and thetuningpin, since the string is deflected under the bar. By beveling thepinblock, as described, the string bending downward at the bridge isheld sufficiently lirm without any pressurebar, and passing directly tothe pin the strain is equally distributed through the entire length ofthe string. Furthermore, by having the pin enter the pin-block firmly atthe surface of the plate, as shown, I am enabled to attach the stringthereto at a point very near the pin-block, which, as above described,cannot be accomplished in the old arrangement, Where the plate has to bedrilled through before reaching the pin-block, and I thus get verylittle leverage on the pin that would tend to loosen the same.

I preferably bore the hole for the pin P diagonally through the bushing,as shown in Fig. 3, the pins themselves being more nearly perpendicularto the surface of the pinblock than the bushings. By this arrangementthe pins, being driven so hard into the bushings, cannot turn therein,being as firm as though held in iron, and, moreover, the bushings, beinginclined at an angle to the pin, cannot by the tension of the strings beturned in the pin-block. As an additional safety device to insureagainst the turning of the bushings, I preferably employ a spline t,which is driven into a groove made before the bushing is inserted alongthe hole in the pin-block and so arranged as to lie partly in thematerial of the bushing, as clearly shown in Fig. at, and partly in thepin-block metal. The pins being entirely supported by wood the tone ofthe strings is entirely free from metallic contact. The holes for thebushings T are not bored entirely through the pinblock, so as to avoidany possibility of the bushings being driven through the pin-block whenthe pins are driven in. Beyond the bushing, however, the pin-block isbored out, as at if, somewhat larger than the pin itself for thereception of the projecting tip of the pin. By this method of insertingthe pins in the pin-block so firm a bearing for the pins is insured thatI am enabled to employ a much thinner and lighter pin-block thanordinarily, by which there is considerable saving of ma terial both inthe plate itself and in the shorter pins required. Moreover, by having athin pin-block there is much less risk in casting, since alargecomparatively thin plate is quite liable to break in cooling if someparts are very much thicker than others by reason of the unequalshrinkage.

The plate in an upright piano is usually supported upon a skeleton orframe, the bars or standards of which run vertically from top to bottom.lVith such a frame it is difficult to employ stay-bolts to fasten theplate to the frame at points where they are most required. I employ aframe (see Figs. 2and 3) in which the timbers O C C 0 run horizontallyand are placed at any point whereby the staybolts I may be placed at themost favorable points to firmly support the plate. The plate is securedto the frame, as shown in Fig. 3,by bolts I screwinginto the top andbottom timbers of the frame, while at any desiredintermediate pointsstay-bolts I, having preferably two nuts 2' t" embracing said plate, asshown, screw into the intermediate horizontal beams C O C C.

The sounding-board D, with its strengthening-ribs d, is secured to theframe in the manner shown in Fig. 3, 0 being pieces interposed betweenthe sounding-board and plate. The sounding-board is bored out, as at B,with holes considerably larger than the staybolts wherever said boltspass through it, in order not to be in contact therewith.

(Z are bridges on the SOLllltlll'lg-bOtltl, over which the strings runnear the bottom thereof, the strings being arranged to run, in the usualmanner, from the pin-block A to the raised ridges A Fig. 1.

The plate A is provided at top and bottom with flanges a.

E E are truss-bolts, each consisting of two parts having ilarin g heads0, countersunk into the flanges a of the plate, the said bolts passingthrough holes in the top and bottom pieces 0 and G and over the beams C,G O C, in the manner shown in Figs. 2 and 3, the two parts forming eachpair being provided with screw-threads at their ends and coupledtogether by right and left handed couplings E, so that any desiredstrain maybe applied to the truss-bolts. Any number of these trussboltsmay be employed running from the top to the bottom flanges of the plateat the back of the frame C 3 being of sufficient number and strung tosuch a tension as to entirely counteract the tendency of the plate tospring through the tension of the strings on its forward surface. -\Viththese truss-bolts and the stay-bolts I the plate, even when madeextremely thin, is rigidly held in place and cannot spring.

The plate and pin-block being made together, it follows that both, withthe springs, may easily be removed from the piano in case of accidentalbreakage of the plate. This cannot be done in the ordinary form ofpiano, since the wooden piirblock is commonly glued or permanentlyfastened to a skeleton separate from the plate and cannot be removedtherewith.

The entire frame O 0 C with the plate bolted thereto in the mannerdescribed, is in my improved instrument fastened in the case by bolts,instead of being glued in, as ordi narily. By simply removing the boltsthe frame and plate may be easily taken out of the case, and by removingthe bolts I I and truss-bolts E the plate and pin-block may be removedfrom the frame, being made in one piece. Moreover, by my improvedconstruction of thin pin-block, in which the tuningpins pass completelythrough, should one pin become broken it may easily be driven out fromthe back without harming the pinblock. A piano thus constructed will notbe seriously affected by changes in atmosphere or climate, since theplate and pin-block are of one piece of metal, so that when once tunedthe instrument will remain in tune a long time.

I claim 1. In a piano, a metal pin-block provided with holes havingbushings, in combination with tuning-pins set in said bushings at aninclination with the central axis of the bushings, substantially as andfor the purposes described.

2. In a piano, a metal pin-block provided with holes having condensedbushings, in combination with tuning-pins set in said bushings at aninclination with the central axis of the bushings, and splines lyingpartly in the material of the pin-block and partly in the bushings,substantially as and for the purposes described.

In a piano, a full metal plate having a pin-block integral therewithprovided with condensed bushings and tuning-pins set therein at an angleto said bushings, said plate having flanges at the top and bottom, incombination With a separate frame bolted to said plate having horizontaltimbers, and truss-bolls connecting the flanges of said plate andpassing over said frame, substantially as and for the purposes.described.

4. In a piano, a full metal plate having a pin-block integral therewithprovided with condensed bushings and tuning pins set therein, said platehaving flanges at the top and bottom, in combination with a separateframe bolted to said plate having horizontal timbers, and truss-bolts,each made in two pieces headed in said flanges and connected by rightand left screw-threaded couplings, whereby the tension of saidtruss-bolts may be varied, substantially as described.

In Witness whereof I have hereunto set my hand.

EDWARD N. (,UMMINGS.

Witnesses:

WM. B. H. Dowsn, ALBERT E. LEAOH.

